Asking Price Range

Estimated MPG

Manufacturer's Suggested Retail Price (MSRP), also known as "sticker" price, is a recommended selling price that automakers give a new car that is above the invoice price paid by the dealer. It is a price that does not include any options that can be added to a particular car style. When shown as a range, the prices are starting MSRPs, without options, for multiple styles for that model.

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Expert Reviews

Expert Reviews 1 of 2

By Kelsey Mays

Cars.com National

December 30, 2009

Editor's note: This review was written in December 2008 about the 2009 Infiniti M45. Little of substance has changed with this year's model. To see what's new for 2010, click here, or check out a side-by-side comparison of the two model years.

A car that's a few years into its current design is usually beginning to show its age, especially when it has as many serious competitors as Infiniti's M sedan does. The M outpaces that trend: The 2006 original took the field by storm and, relatively speaking, today's car is eight-tenths as terrific. In a segment whose players' strengths vary across many fronts — performance, technology, quality, reliability — the M emerges a competent choice across the board.

Infiniti sells two variants, the V-6 M35 and the V-8 M45. All-wheel-drive versions of both are also available, dubbed M35x and M45x. Ever since the brand dropped the larger Q45, the M has become its de facto flagship. As such, it's enjoyed frequent updates to stay competitive. The 2009 model sports an upgraded V-6 drivetrain, while the V-8 carries over with minimal differences. Click here to see a comparison with the 2008 model, whose review serves as the basis for this one.

I tested an '09 M35x, though I've also driven a 2008 M35 and 2006 M45.

Going & StoppingThe M35 should be fine for most drivers, as Infiniti tuned its V-6 this year for more high-revving horsepower — an impressive 303 hp, to be exact — but less torque, which is the low-end grunt you feel when pulling away from a stoplight. Even so, I found gobs of fluid power with no peaky bursts or sluggishness starting out, and under hard acceleration the high-pitched exhaust note should be music to any gearhead. The engine revs a bit more freely but doesn't feel noticeably stronger than last year's 275-hp M35, and dollar for dollar, it still provides a richer powerband than competitors like the BMW 528i or Audi A6 3.2. Even Hyundai's 3.8-liter Genesis, an impressive bargain alternative for this segment, feels less spirited.

This year's rear-wheel-drive M35 gets Infiniti's new seven-speed automatic; it moves gas mileage up a few ticks versus last year's version, which had a five-speed automatic. Other models, including the M35x I tested, carry over the five-speed. Though it's a gear or two short of the competition, that transmission remains one of my favorites. It holds lower gears tenaciously at lower speeds, refusing the mileage bait of an early upshift while you're still on the gas. Shifts are heard in engine pitch but rarely felt, and highway kickdown is quick and free of gear-hunting. Around town, lower gears arrive almost instinctively — accelerating out of a corner or pulling around a semi, for instance, you're rarely caught flat-footed in a higher gear. Jaguar's ZF automatic comes to mind in the same league, and I hope Infiniti preserved this sort of performance in the M35's seven-speed. Every M this year gets a Drive Sport mode that holds lower gears longer for more responsiveness, but it's hardly necessary.

If the M35 is confident, the M45 is authoritative. Don't let the mere 22-hp difference fool you — with an extra liter of displacement, the M45's V-8 boasts a torque peak that's 800 rpm lower, with 74 more pounds-feet of twist. It trades the M35's finesse for brute hang-the-tail-out power at pretty much any speed. In my brief time with the M45, years ago, I found the acceleration unmanageable at times. It would come in spurts, particularly through second and third gear, giving the car a restless feeling on city streets. If your commute involves roads that are open enough for the M45 to stretch its legs, though, it could be serious fun.

The M35x and M45x utilize an all-wheel-drive system that transfers power forward or backward electronically. It can split power from 50/50 front/rear all the way to 0/100, with all the power going to the rear wheels to optimize handling. Infiniti sums up the system's convoluted name with the equally convoluted acronym ATTESA E-TS — which, were it an actual word, would be a great way to dump all your T's in Scrabble.

Drivetrains: M35 vs. M45

M35

M45

Engine

3.5-liter V-6

4.5-liter V-8

Horsepower (@ rpm)

303 @ 6,800

325 @ 6,400

Torque (lbs.-ft. @ rpm)

262 @ 4,800

336 @ 4,000

Transmissions

7-speed auto (M35); 5-speed auto (M35x)

5-speed auto (M45 and M45x)

EPA gas mileage (city/hwy., mpg)

17/25 (M35); 16/22 (M35x)

16/21 (M45); 14/20 (M45x)

Fuel type

Premium (recommended)

Premium (required)

Source: Automaker and EPA data

Four-wheel-discantilock brakes are standard, and the systems are identical on the M35 and M45. Last year's M35 had a somewhat mushy pedal for this class, but the M45 I tested in 2006 had more linear braking.

Ride & HandlingMidsize luxury cars run the gamut from comfortable to rigid; the M is closer to rigid, though not so much that it's punishing to drive. My test car last year had the Sport package — which augments the four-wheel-independent suspension with sportier tuning, bigger wheels and high-performance summer tires — but ride quality was livable, and even more so in the M35x I drove this year, which had smaller wheels and regular suspension tuning. Highway road noise remains tolerable up to 75 mph — above that, wind and road noise quickly encroach — and the car's chassis dispatches bumps with modest noise and few reverberations.

If you live near curvy roads, you'd do well to drive them in the M. The steering wheel moves with a lighter touch than in Infiniti's smaller G37, and though it doesn't feel as precise in prolonged bends — highway cloverleafs, curvy backroads — the turn-in precision for lane changes and most city driving is in the same league. The steering feel encourages twisty-road driving in a way a Volvo S80 or Mercedes E-Class cannot. Body roll remains well in check, and at its limits the M displays good grip and even better balance. The Sport package adds Infiniti's Rear Active Steer, which power-adjusts the suspension hardware to angle the rear wheels slightly while the car is turning. The purported result is swifter handling. Last year's M35 came equipped with the feature, but I couldn't tell when the system was operating, or what benefits it added. The M never once came off as unresponsive, though, so evidently the extra hardware did its job.

Rear-wheel-drive models increase the M's turning circle to 36.7 feet, as opposed to 36.1 feet with all-wheel drive. Those figures are on the tighter side of the competition.

Originally lauded for its quality relative to Infiniti's previous efforts, the M's cabin has held up well thus far. The dashboard rises to the windshield in steps, giving the cabin a roomy feel. Interior surfaces aren't as sumptuous as those in the E-Class or Jaguar XF, but they're certainly upscale enough: There are leather wrappings around the door pulls and chrome runners along the steering wheel. The cabin trim — aluminum or optional wood — is the real deal, not synthetic.

Audio options range from a six-speaker, six-CD stereo to two Bose systems with eight and 14 speakers, respectively. I've spent the most time with the eight-speaker system, which proved rich enough for my taste. I don't think I'd go for the top-shelf upgrade, considering it also shoehorns a bulky DVD-audio disc drive in the center console.

The navigation system's graphics are getting a bit dated, but its layout generally wallops the competition. Users can touch the on-screen commands or any of numerous shortcut buttons to zoom in or out, move the cursor around the map, go back to the previous screen, you name it. The intersection input lets you search within a specified city — a clear advantage over systems that aggravatingly display every Third and Main in eight surrounding states.

Real-time traffic uses a feed from XM's NavTraffic subscription service to depict congestion levels with color-coded lines along the highway. It can find the quickest route to your destination based on current traffic conditions, something early real-time traffic navigation systems didn't do. On one trip up Chicago's Interstate 90in last year's M35, the system reported that my route was largely congestion-free — while I sat in bumper-to-bumper traffic. I'll note, at least, that it rarely overreported traffic. Infiniti says the feed goes from XM to all models with NavTraffic, so this would likely be an issue in any car with the system.

Seating & CargoFour of the M's five seats offer ample legroom and headroom, but the bulky floor hump in back means a fifth passenger has to share foot room. The front seats have standard 10-way power adjustments, and there's plenty of range for taller drivers. After you park, the steering wheel automatically powers upward to ease exit and entry — and does so much faster than in some of the more cantankerous steering columns in the M's peers.

Maximum cabin volume is 105.2 cubic feet, and trunk volume is 14.9 cubic feet. Like most cars in this class, the M lacks a folding backseat. There's a center pass-thru for skis or other long items, but it's fairly small. (If you want a car with a folding seat in this segment, try the E-Class or XF.)

Cabin & Cargo Compared (cu. ft.)

Cabin volume

Trunk volume

Hyundai Genesis

109.4

15.9

Lexus GS

109.1

12.7

Lincoln MKS*

105.8

18.7

Infiniti M

105.2**

14.9

Cadillac STS*

102.9

13.8

BMW 5 Series

99.1

14.0

Acura RL

99.1

13.1

Jaguar XF

99.0

17.7

Audi A6

98.0

15.9

Volvo S80

98.0

14.9

Mercedes-Benz E-Class

97.2

15.9

*Does not include a standard moonroof. Volumes for other cars are listed with moonroofs.**103.1 cubic feet with Premium Package.All data for 2009 models except 2008 Audi A6.

Safety & ReliabilityIn crash tests by the Insurance Institute for Highway Safety, the M earned the top possible score, Good, in both frontal and side-impact tests. Standard safety features include six airbags, with side-impact airbags for the front seats and side curtain ones for both rows, as well as four-wheel-disc antilock brakes, traction control and an electronic stability system. Front-seat occupants have active head restraints and pre-crash seat belts that cinch up during extreme braking to prepare occupants for impact. Also standard on all models are xenon headlights with an adaptive lighting system than can swivel the lights a few degrees during a turn to help illuminate corners. Last year the M35x didn't include them standard.

Opt for the Advanced Technology Package — which first requires the regular Technology Package — and you get adaptive cruise control, Preview Braking and Lane Departure Prevention. Adaptive cruise control uses a laser beam to judge the distance to the car ahead and apply modest (not full) gas or brakes to maintain a proper distance. Preview Braking uses the same lasers to sense any oncoming obstructions, including a rapidly slowing vehicle. Though it won't actually begin braking for you, as the system in the FX crossover does, it will alert the driver with an audio chime and pre-load the brakes for sharper response.

Lane Departure Prevention debuted in the EX35 SUV a couple years back. It builds on the Lane Departure Warning system Infiniti has offered for two years now. Both use a camera mounted behind the windshield to pick up lane markings and warn the driver if the car is drifting astray; LDP goes one step further by applying individual brakes to nudge the car back on course. My test car didn't have it, but I've used the feature in the EX and it's pretty impressive. Contrary to its Big Brother overtones, LDP works subtly: Hit a turn signal or turn the wheel more than a couple degrees in the EX and you'll override it. Don't think of LDP as some kind of bowling-alley gutter bumper — it works gently but meticulously. Aside from an audible warning chime, the most you'll notice is a slight tug on the wheel and a hint of deceleration as the brakes nudge the car back into its lane. Infiniti spokesman Kyle Bazemore told me the systems in the M and EX are identical, and both can be switched off if they prove too intrusive.

Reliability has proved impressive, with the M garnering top scores in Consumer Reports studies in recent years. The publication predicts the 2009 model will fare better or much better than average, depending on the variant you purchase. That's a rating that just edges out the RL, A6 and GS and considerably beats the 5 Series, E-Class and STS.

Features & PricingThe M35 starts at $45,800, which is within range of most V-6 competitors, save the bargain-priced Genesis. It's lavishly equipped at that, with leather upholstery, dual-zone A/C, a moonroof and power front seats with heating and cooling, all standard. That price also gets you a six-speaker, six-CD stereo with an auxiliary jack for MP3 players. The M45 starts at $52,150; besides the V-8 engine, it doesn't add much other equipment. Both offer all-wheel drive and a Sport package, but you have to pick one or the other.

Options include heated and power-reclining rear seats, a navigation system with a backup camera, the two Bose audio systems and a backseat DVD player. Check all the boxes, and a loaded M45x — whose poor mileage incurs a $1,300 gas-guzzler tax — runs around $67,500.

M in the MarketThe M is as competitive as ever, and not just in a practical way. This car is fun — to drive, to look at, to sit in. In a field of climbing prices and checkered quality, it's nice to see an old favorite hold up so well.